| In our country and all over the world of traditional industry,by-products and excess raw material of industrial reaction,these separation are invested a large amount of capital resources,energy consumption accounted for the total industrial energy consumption of 40%-60%,so the industry separation method of a low energy consumption is very important.High efficiency?low cost advantages and the sustainable development of membrane separation are already more and more noticed by people.At present,CO2 is separated by imembrane of technology that is considered to have champaign market prospects,ZSM-5 membrane has a uniform channel excellent resistance to high temperature and alkali corrosion resistance good hydrothermal stability,has been widely aplied in areas such as anticorrosive coating material separation chemical sensor,b-axis orientation of MFI zeolite membrane has a lot of advantages,such as mass transfer resistance is small,the distance is short and so forth.In addition it is the most conducive to separate.how to through the diauxic growth prepare orientation ZSM-5 membrane,the preparation of highly b-axis oriented grain layer is the key.The langmuir-blodgett method for preparation of grain layers is the focus of our research group.This study will give full play to the advantages of LB method and promote it Include:1.Based on the previous research of our research group,According to the law of LB,the highest b-axis oriented silicalite-1 grain layer was firstly prepared,ZSM-5 membrane with high b-axis orientation was synthesized with different templates.Finally,different methods were used to repair high-temperature roasting ZSM-5 membrane after removal of template.The results showed that dimer-TPAOH was used as the template of secondary growth,the CPO{0k0)value was up to 0.858,with little twins,thin thickness and higher b-axis orientation.The results show that the regrowth method has little effect on the thickness of zeolite membrane.However,the selectivity after repair was lower than that of polystyrene/toluene.PDMS/n-heptane repair was used to regulate the pores of zeolite membrane.Although it has higher selectivity,the thickness of zeolite membrane itself and the permeability rate of single component gas increase obviously.2.ZSM-5 membranes with different Si/Al ratios were successfully prepared by regulating the ratio of secondary growth solution,and the gas separation energy was systematically studied.The results show that the thickness of ZSM-5 molecular sieve with dimer-tpabr as template for secondary growth and 48h crystallization time decreases with the increase of surface twins and secondary nucleation.According to the gas separation performance,the oriented ZSM-5 zeolite membrane with the re-growth repair method has a high flux when separating C02/H2 mixture,but its separation coefficient is low,only 5.27.The separation coefficient of C02/H2 mixture was 8.25 by using polystyrene/toluene repair method.Although the separation coefficient of C02/H2 mixture reached 10.14,the penetration rate of CO2 molecule was only 5.25×10-9mol m2/(s-Pa).The research contents systematically analyzed the influence of aluminum ion content and osmotic pressure on the separation performance of ZSM-5 membrane,providing rigorous research data for the industrial separation of CO2 molecules by zeolite membrane.3.Reverse osmosis desalination performance of ZSM-5 membrane repaired by different methods was studied,the results showed that the oriented ZSM-5 zeolite membrane with PDMS/n-heptane repair had the highest retention rate at the same time,In the experiment for 96 h,withholding rate of 79.6%,orientation ZSM-5 zeolite membrane in the process of RO desalination,permeate flux due to the influence of the concentration polarization,as the growth of the time have a significantly lower,while the intercept rate due to adsorption of the electronic structure of the overlaping double,reverse osmosis desalination process,permeate flux and entrapment rate were increased with the concentration of penetrating fluid. |
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